kernel/drivers/clk/clk-twl6040.c

   1 /*
   2 * TWL6040 clock module driver for OMAP4 McPDM functional clock
   3 *
   4 * Copyright (C) 2012 Texas Instruments Inc.
   5 * Peter Ujfalusi <peter.ujfalusi@ti.com>
   6 *
   7 * This program is free software; you can redistribute it and/or
   8 * modify it under the terms of the GNU General Public License
   9 * version 2 as published by the Free Software Foundation.
  10 *
  11 * This program is distributed in the hope that it will be useful, but
  12 * WITHOUT ANY WARRANTY; without even the implied warranty of
  13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14 * General Public License for more details.
  15 *
  16 * You should have received a copy of the GNU General Public License
  17 * along with this program; if not, write to the Free Software
  18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  19 * 02110-1301 USA
  20 *
  21 */
  22
  23 #include <linux/module.h>
  24 #include <linux/slab.h>
  25 #include <linux/platform_device.h>
  26 #include <linux/mfd/twl6040.h>
  27 #include <linux/clk-provider.h>
  28
  29 struct twl6040_clk {
  30         struct twl6040 *twl6040;
  31         struct device *dev;
  32         struct clk_hw mcpdm_fclk;
  33         struct clk *clk;
  34         int enabled;
  35 };
  36
  37 static int twl6040_bitclk_is_enabled(struct clk_hw *hw)
  38 {
  39         struct twl6040_clk *twl6040_clk = container_of(hw, struct twl6040_clk,
  40                                                        mcpdm_fclk);
  41         return twl6040_clk->enabled;
  42 }
  43
  44 static int twl6040_bitclk_prepare(struct clk_hw *hw)
  45 {
  46         struct twl6040_clk *twl6040_clk = container_of(hw, struct twl6040_clk,
  47                                                        mcpdm_fclk);
  48         int ret;
  49
  50         ret = twl6040_power(twl6040_clk->twl6040, 1);
  51         if (!ret)
  52                 twl6040_clk->enabled = 1;
  53
  54         return ret;
  55 }
  56
  57 static void twl6040_bitclk_unprepare(struct clk_hw *hw)
  58 {
  59         struct twl6040_clk *twl6040_clk = container_of(hw, struct twl6040_clk,
  60                                                        mcpdm_fclk);
  61         int ret;
  62
  63         ret = twl6040_power(twl6040_clk->twl6040, 0);
  64         if (!ret)
  65                 twl6040_clk->enabled = 0;
  66 }
  67
  68 static const struct clk_ops twl6040_mcpdm_ops = {
  69         .is_enabled = twl6040_bitclk_is_enabled,
  70         .prepare = twl6040_bitclk_prepare,
  71         .unprepare = twl6040_bitclk_unprepare,
  72 };
  73
  74 static struct clk_init_data wm831x_clkout_init = {
  75         .name = "mcpdm_fclk",
  76         .ops = &twl6040_mcpdm_ops,
  77         .flags = CLK_IS_ROOT,
  78 };
  79
  80 static int twl6040_clk_probe(struct platform_device *pdev)
  81 {
  82         struct twl6040 *twl6040 = dev_get_drvdata(pdev->dev.parent);
  83         struct twl6040_clk *clkdata;
  84
  85         clkdata = devm_kzalloc(&pdev->dev, sizeof(*clkdata), GFP_KERNEL);
  86         if (!clkdata)
  87                 return -ENOMEM;
  88
  89         clkdata->dev = &pdev->dev;
  90         clkdata->twl6040 = twl6040;
  91
  92         clkdata->mcpdm_fclk.init = &wm831x_clkout_init;
  93         clkdata->clk = devm_clk_register(&pdev->dev, &clkdata->mcpdm_fclk);
  94         if (IS_ERR(clkdata->clk))
  95                 return PTR_ERR(clkdata->clk);
  96
  97         platform_set_drvdata(pdev, clkdata);
  98
  99         return 0;
 100 }
 101
 102 static struct platform_driver twl6040_clk_driver = {
 103         .driver = {
 104                 .name = "twl6040-clk",
 105         },
 106         .probe = twl6040_clk_probe,
 107 };
 108
 109 module_platform_driver(twl6040_clk_driver);
 110
 111 MODULE_DESCRIPTION("TWL6040 clock driver for McPDM functional clock");
 112 MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>");
 113 MODULE_ALIAS("platform:twl6040-clk");
 114 MODULE_LICENSE("GPL");